Look at
http://members.chello.nl/epzachte/Wikipedia
You will find lots of info about Wikipedia for Pocket PC/Palm/EPOC using TomeRaider text browser.
There is also a link to a Perl script.
http://members.chello.nl/epzachte/Wi.../WikiToTome.pl
This Perl script processes the Wikipedia SQL dump and produces mentioned files.
Feel free to adapt it to other database managers.
And yes, handheld memory is expensive, but prices are falling steadily. I'm glad I bought a compact flash compatible device. CF is way ahead in capacity and low in price (I use a 1GB card).